The recipe -
Leave the film to soak in the bleach for around half an hour, then bring the bleach to the boil and simmer gently for around 10 minutes. Remove film from bleach and put in the dishwasher on it's most intensive cycle. Remove from the dishwasher and blast with the hairdryer for as long as you can be bothered. Finally leave on a radiator for a month while you go on holiday. :D